Pivoted sweep arm bender



etc 7 1958 F. A. ENGBERT PIVOTED SWEEP ARM BENDER 2 Sheets-Sheet 1 Filed April 4, 1955 Get. 7, 1958 F. A. ENGBERT 2,855,019

PIVOTED SWEEP ARM BENDER Filed April 4, 1955 2 Sheets-Sheet 2 mo 36 34 28 10. 5 134 g2 g6 ,J

aw/a w 12 ORA/E United States Patent PIVOTED SWEEP ARM BENDER Francis A. Engbert, St. Louis, Mo.

Application April 4, 1955, Serial No. 498,970

1 Claim. (Cl. 153-46) The present invention relates generally to stock forming devices, and more particularly to a power-operated machine for forming arcuate bends in rod, strip and tubular stock. 4

Briefly, the invention contemplates a device comprising a center pivot post having a radius appropriate to form the desired inside curvature of a strip which is to be bent therearound. This pivot post is at the center of a rotatable table which carries a roller so spaced from the pivot post as to accommodate an article of stock, such as a wire, rod, strip, or tube, therebetween. Stationary stops and guides are provided for holding the stock in position so that the bend may be formed at a desired point, and power-operated means are provided for pivoting the table and the roller so as to wrap the stock around the center pivot post. An adjustable stop is provided for limiting the extent of the wrapping action to provide the desired degree of bend.

It is an object of the present invention, therefore, to provide a novel stock bending machine which operates under the simple principle of inducing a wrapping action about a forming element having a selected radius.

It is another object of the invention to provide a power-operated stock bending machine in which elongated strips may be placed without the necessity for clamping or otherwise securing them in place prior to initiating a bending operation.

It is another object of the invention to provide a novel stock bending machine which is readily adjustable to accommodate various articles and sizes of stock, and to form bends therein to various radii and degrees of curvature.

It is another object of the invention to provide a novel power-operated stock bending machine which is simple and flexible in its structural arrangement, fast and accurate. in its action, and whichrequires minimum skill in its operation.

The foregoing, along with additional objects and advantages, will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure l is a top plan view of a stock bending machine conforming to the present invention, a hood which covers certain of the moving elements being shown in section; Figure 2 is a side elevational view of the machine of Figure 1, a portion of the hood being broken away in order to reveal certain operative elements of the machine;

Figure 3 is a fragmentary rear elevational view of the machine;

I Figure 4 is an enlarged vertical section taken generally along the line 44 of Figure l; l

Figure 5 is a vertical section taken generally along the line 5-5 of Figure 1;

Figure 6 is an enlarged vertical section taken-generally .along the line 6-6 of Figure. 1;

Figure 7 is a vertical section taken generally along Figure 8 is a fragmentary top plan view illustrating the manner in which the machine of the present invention performs a rod bending operation;

Figure 9 is an enlarged fragmentary vertical section generally similar to Figure 4, but illustrating a center pivot post of different radius, along with a different type of stock to be bent;

Figure 10 is a fragmentary plan view generally similar to Figure 8, but illustrating a bending operation performed upon an exceptionally short piece of stock;

Figure 11 is an enlarged top plan view of a removed guide member;

Figure 12 is an enlarged top plan view of a removed spindle;

Figure 13 is an enlarged bottom plan view of a circular table;

Figure 14 is a fragmentary topplan view illustrating the manner in which the machine of the present invention is modified for the bending of tubular stock;

Figure 15 is a vertical section of a tube bending roller;

Figure 16 is a side elevational view of a removed tube bending pivot post; I

Figure 17 illustrates a typical bend formed in a piece of round rod;

Figure 18 illustrates a typical bend formed in rectangular rod stock; and

Figure 19 illustrates typical bends formed in flat strip stock.

Referring to the drawings more particularly by the use of reference characters, the numeral 20 designates generally a stock bending machine constructed in accordance with the teachings of the present invention. As major components, the machine 20 comprises a bending assembly 22 and a power assembly 24, both of which are mounted on a common base plate 26.

Considering first the bending assembly 22, a bed member 28 of rectangular shape as illustrated in Figures 1, 8 and 10, is supported upon four posts 30 so as to dispose it at a convenient elevation above the base plate 26. The mode of attachment of the posts 30 to the plate 26 and to the member 28 is immaterial as long as an appropriately rigid structure is provided. Preferably, the member 28 has a depending boss portion 32, clearly illustrated in Figure 4, which is bored out on a vertical axis to receive a spindle 34 mounted for rotation in bearings 36 and 38. Besides being provided with appropriate recesses for the bearings 36 and 38, the bed member 28 has a shallow, circular recess 40 of relatively large diameter which rotatably receives a circular table 42 secured to the spindle 34 for rotation therewith.

The table 42 has a central hole 44 which is coextensive with a central hole 46 in the spindle 34, and the parts 42 and 34 are secured together by means of screws 48,

shown in Figures 1 and 8. Figure 12, which shows an upper end View of the spindle 34, depicts threaded holes 50 for receiving the screws 48, and Figure 13, which shows a bottom plan view of the table 42, illustrates countersunk holes 52 by means of which the heads of the screws 48 are disposed at least flush with the upper surface of the table 42.

Figure 13 also clearly illustrates a T-slot 54 formed in the table 42 and having its axis coincident with a radial line of the table. Figures 4 and 9 then illustrate the manner in which a roller assembly 56 is adjustably secured in the T-slot 54 so as to stand upright above the upper surface of the table 42. The roller assembly 56 comprises a headed pin 58, having a central cylindrical portion 60, and a lower portion 62 of reduced diameter threaded to receive a nut 64. The cylindrical portion has a diameter greater than the open width of the T-slot 54 so that the pin 58 can be secured firmly to the table 42 at any point along the slot 54. Preferably, the lower recessed portion of the T-slot 54 is of a width that is only slightly greater than the width of the nut 64 across the flats, so that the nut will not turn when it is desired either to secure or to loosen the roller assembly 56. An annular roller 66 fits rotatably over the cylindrical portion 60 and has a vertical height which is slightly less than that of the portion 60. Thus, the roller 66 is freely rotatable when the assembly 56 is secured in place. A special purpose roller 66", formed with an arcuately grooved periphery as shown in Figure 15, replaces the fiat faced roller 66 when it is desired to bend tubular stock in the machine 20.

A center pivot post 68 comprising a cylindrical forming portion 70 having a cylindrical mounting portion 72 is disposed upright at the center of the table 42 with the mounting portion 72 occupying the hole 44 in the table 42 and the upper end of the hole 46 in the spindle 34. As will appear more fully hereinafter, the machine 20 may employ pivot posts having forming sections of various shapes, heights, and diameters. Figure 9, for example, illustrates a pivot post 68' having a cylindrical forming section 7 which has less height, but greater diameter than the post 68. Figures 14 and 16 show a more specialized forming section 70", which is provided with a concave periphery 71 for accommodating tubular stock. The circular post 70" is cut off along a chord, as illustrated in the drawing at 73, to facilitate removal of the stock after the bending operation, and upstanding pins 74 are provided for manually rotating the post 70", as will appear. Any of the illustrated posts, or others, may be inserted in the machine 20 or withdrawn therefrom at will, depending upon the requirements of the bending operation to be performed.

A guide member 75 formed as clearly illustrated in Figure 11, with parallel slots 76, is adjustably secured by means of a U-shaped holder 78 and cap screws 80 to the upper surface of the bed member 28 so as to overlie the circular table 42 as clearly illustrated in Figures 1, 8 and 10. Figure 7 illustrates the above-described attachment in detail. Thus mounted, the guide member 75 may obviously be adjusted so as to dispose a vertical end surface 82 at various distances from a line which could be drawn parallel to the surface 82 and tangent to the forming section of whatever center pivot post might be em ployed.

A bracket rod 84 is threadedly received in the bed member 28 so as to extend horizontally therefrom as best illustrated in Figures 1 and 2. A jam nut 86 is provided to secure the bracket rod 84 against inadvertent loosening. It will be noted that the bracket rod 84 extends in a direction which is parallel to the extent of the vertical guide surface 82 of the guide member 75. A stop gauge assembly 88, constructed with the simple clamping arrangement illustrated in Figure 6, is mounted on the bracket rod 84 and includes a member 90 extending perpendicularly from the rod 84 a distance sufficient to bring it approximately opposite the vertical axis of the table 42. A rod 92 is mounted by any appropriate means adjacent the free end of the member 90, so asto extend perpendicularly therefrom as illustrated in Figures 1 and 2. Clearly, the arrangement is uch that the assembly 88 may be disposed at any point along the rod 84, either with the rod 92 projecting to the left as illustrated in Figures 1 and 2, or to the right as illustrated in Figure 10. A screw 94 is provided for securing the assembly 88 in adjusted position.

Directing attention now to the power assembly 24, a double-acting pneumatic cylinder 96 is secured to the base plate 26 so as to extend its reciprocating piston rod 98 generally toward the forming assembly 22. Thus disposed, the piston rod 98 extends freely through an apertured upright portion 100 of a stop bracket 102 shaped as clearly illustrated in Figures 1, 2 and 5. The member 102 is adjustably secured by means of nut and bolt assemblies 104 to parallel rails 106 secured in any suitable man- 4 ner to the base plate 26 so as to provide a T-slot arrangement.

A rack assembly 108 comprising a toothed rack 110 having one end pivotally secured by means of a pivot pin 112 to a clevis end 114 of a threaded collar 116 is connected by means of the collar 116 to the free end of the reciprocating piston rod 98. As best illustrated in Figure 4, the back or nontoothed side of the rack 110 is slidably received in a rectangular notch 118 formed in a bracket plate 120 secured by any convenient means so as to depend from the bed member 28.

The gear rack 110 drivingly engages a pinion gear 122 keyed to a lower portion 124 of the rotatable spindle 34. A plate washer 126 and nuts 128 serve to retain the gear 122 on the spindle 34.

A hood 130 formed to the cross section best shown in Figure 5 covers most of the power assembly 24, and at the same time forms a table-like extension at the level of the upper surface of the bed member 28. One end of the hood 130 i pivotally secured by screws 132 to the base plate 26, while the other end rests upon pins 134 pressed into the plate 26. Notches 136 accommodate the pins 134. Air hoses 140, for supplying compressed air to the pneumatic cylinder assembly 24, are extended from the open end of the hood 130 as illustrated.

Operation From the foregoing description, it will be appreciated that the stock bending machine 20 is a versatile device which may be employed for bending many different tock items to various arcuate configurations. It is particularly useful as a production machine for making identical bends in mass produced articles. To illustrate, let it be assumed that a straight, round rod, such as indicated by the letter R in Figure l, is to be given a bend as illustrated in Figure 8. The operator, knowing the desired inside radiu-s of the bend to be imparted to the red R, selects a central pivot post, such as 68, of appropriate diameter and mounts it on the table 42. One of the rods R is then laid up against the post 68 so that it extends parallel to the bracket rod 84, and the guide plate 75 is moved to a position wherein its vertical surface 82 abuts the rod R. The roller assembly 56 is also moved up to abut the rod R and is then backed off a slight amount as indicated in Figure 4. The forming mechanism having been set, the stop bracket 102 is adjusted lengthwise of the piston rod 98 so as to limit the retracting stroke of the piston rod 98 at the point the desired bend in the rod R will have been achieved. This condition is clearly illustrated in Figure 8, wherein the collar 116 is shown in abutment with the upright portion 100 of the stop bracket 102 under which condition the table 42 with the roller assembly 56 mounted thereon has pivoted to the position shown.

The final adjustment is that of the gauge assembly 88. The assembly 88 is adjustably positioned along the bracket rod 84 so that the rod R, when abutted therewith, will be in a position such that the bend is formed at the proper place.

With the machine 20 adjusted as above described, the operator has only to lay a rod R in the position illustrated in Figure 1 and then to actuate the cylinder assembly 24 so as to reciprocate the piston rod 98 and the attached gear rack 110 from the position of Figure 1 to the position of Figure 8 and return. This actuation of the cylinder assembly 24 is preferably achieved through use of a conventional pedal-operated valve (not shown) which requires only that the pedal be depressed and released in order to achieve the above-described reciprocation of parts. Clearly, the reciprocation of the gear rack 110 pivots the gear 122 and the parts, including the table 42 and the roller assembly 56, attached thereto. The resulting pivotal movement of the table causes the roller assembly 56 to wipe the rod R around the central pivot post 68 and thereby to impart the desired bend. The operation is accomplished very quickly, whereupon the operator removes the bent rod R and lays another rod R in position to be bent.

The above-described adjustment and operation of the machine 20 is substantially the same for different shapes of stock and for different types of bends. Figure 9, for example, illustrates the use of the pivot post 68' of relatively large diameter for bending a flat strip designated by the letter F.

In the event that the items to be bent are so short as to fail to extend beyond the edge of the bed member 28, the gauge assembly 88 may be reversed on the bracket rod 84 as illustrated in Figure 10. In its reversed position, the rod 92 extends over the top of the bed member 28 sufficiently to engage the end of the stock piece S.

When hollow stock, such as tubing, is to be bent in the machine 20, special forming elements are used in order to avoid collapse of the stock at the bend. Thus, as illustrated in Figure 14, a piece of tubular stock T may be accommodated by merely substituting a pivot post having a grooved forming section such as 70" and employing a grooved roller such as 66" in cooperation therewith. The previously described discontinuity of the armately grooved periphery 71 permits the bent stock to be removed without resort to dragging it out lengthwise. Thus, upon return of the roller 66" from its position as illustrated in Figure 14 to its starting position adjacent the guide plate 75, it is only necessary to rotate the member 70 so as to dispose its vertical edge 73 in parallel opposition to the vertical guide surface 82, whereupon a slight forward movement of the tube T will enable it to,

be lifted from the table 42. The finger pins 74 are used for adjusting the grooved pivot post to a position wherein the above-mentioned discontinuity will not interfere with the bending operation, and also for moving the post to the aforesaid advantageous position for removal of the bent tube.

Figures 17, 18 and 19 illustrate typical stock pieces and bends formed therein with the machine 20. Thus, Figure 17 shows round stock bent substantially to the form of an eye. Figure 18 shows rectangular stock bent well past'the point of 180 reversal, and Figure 19 illustrates fiat strip stock having a series of 90 bends formed therein.

Clearly, there has been provided a stock bending machine which fulfills the objects and advantages sought therefor.

It is to be understood that the foregoing description and the accompanying drawings have been given only by Way of illustration and example. It is further to be understood that changes in the form of the elements, rearrangements of parts, or substitution of equivalent elements, all of which will be apparent to those skilled in the art, are contemplated as being within the scope of the invention, which is limited only by the claim which follows.

What is claimed is:

In a stock bending machine, in combination, a stationary base, a table-like member rotatably mounted on the base, a peripherally grooved post member of generally circular plan form except for relief along one chord of the otherwise circular form disposed at the center of rotation of the table-like member in coaxial upstanding relation therewith, said post member being rotatably mounted with respect to the table-like member and having upstanding finger engageable means for manually positioning the post member, a stock engaging assembly mounted on said table-like member in upstanding spaced relation to said post member, said stock engaging assembly comprising a peripherally grooved circular roller, guide means adjustably secured to the base for positioning and retaining a length of stock in interposed relation between said post member and said roller, and means for oscillating said table through a predetermined portion of a revolution so as to wrap the stock partially around the post member.

References Qited in the file of this patent UNITED STATES PATENTS 690,023 Hampson Dec. 31, 1901 898,424 Bartlett Sept. 15, 1908 1,016,700 McHugh Feb. 6, 1912 1,020,582 Straus Mar. 19, 1912 1,277,235 McKenna Aug. 27, 1918 2,055,955 Wagenbach Sept. 29, 1936 2,128,620 Lyons Aug. 30, 1938 2,153,935 Neukirch Apr. 11, 1939 2,349,525 St. Clair May 23, 1944 2,430,899 Wallace Nov. 18, 1947 2,453,868 Shaw Nov. 16, 1948 2,454,290 Payne Nov. 23, 1948 2,491,893 Duer Dec. 20, 1949 2,770,262 Ganci Nov. 13, 1956 FOREIGN PATENTS 156,462 France July 9, 1883 61,971 Switzerland Aug. 23, 1912 459,293 Italy Sept. 1, 1950 

